Inertia Exam Review


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Know what forces are involved in an object spinning in a circle, and know what happens when the centering force is removed
The centering force is the Centripetal Force. It is usually the tension in the string, or gravity between the orbiting objects. The force causes the object to keep changing it's direction. When the centripetal force is removed, the object will contine going in a straight line, at a constant speed, unless acted on by a non-zero net force
What happens when an object is pushed with a force equal to the force of friction?
The object will move at a constant velocity.
Why isn't a satellite in orbit moving at a constant velocity
The direction is constantly changing
When Galileo rolled a ball down the ramp, how far up would it roll?
To nearly it's original height
What did Copernicus state publicly?
That the Earth revolves around the sun
In which direction does friction act?
Friction always acts to the opposite direction
What does the law of inertia state?
An object will
Continue moving at a constant velocity
Continue moving in a straight line
Remain at rest
Not ever been working unless acted upon by a non-zero net force
Does the law of inertia apply more to object at rest, or objects in motion?
Both moving and non moving objects
Imagine that a rock is thrown into frictionless space. How much force is required to keep it going?
None. You don't need a net force to keep things moving, only to CHANGE their motion. Once something is moving. It will keep moving
What would happen if gravity suddenly stopped acting on planets? Which way would they all move?
They would move in straight lines tangent to their others
You can pull a tablecloth out from under a place setting without toppling everything. Why can this be done?
Because inertia is a property of matter
How much force is required to maintain an object at a constant velocity in frictionless space?
None Force
How much acceleration does an object experience if it is moving at a constant 30 m/s in a straight line?
None acceleration
What is friction? How does it act? What causes it?
It's a force that acts between surfaces that are sliding past each other, and it acts in a direction opposite to the motion of an object. It comes from microscopic bumps in the surfaces of an object
If one object has twice the mass of another, how much more inertia does it have?
Twice the inertia
Does a 50 kg object weigh more, less, or the same, on the Moon as it does on Earth?
Less on the moon
Which has more mass, a kilogram of iron, or a kilogram of balloons?
They have the same mass because a kilogram is a Unit of mass and 1kg = 1kg
An object weighs 50 N on Earth. A different object weighs 50 N on the Moon. Which object is heavier? A separate question: which object has a greater mass?
An object that weighs 50 N on Earth is heavier because Earth and gravity is directly proportional. Mass and weight is also directly proportional. Earth has more mass than the moon so objects would then weigh more on Earth than the moon.
How did Aristotle describe violent motion?
He described violent motion as an imposed motion, a result of a force pushed or pulled.